1. Field of the Invention
The present invention relates to an axial-flow compressor that is used for gas turbine or the like and a method for modifying an axial-flow compressor.
2. Description of the Related Art
In recent years, an axial-flow compressor has been modified in many cases so that a pressure ratio of the axial-flow compressor is high in order to improve performance of a gas turbine. Traditionally, variable stator vanes of an axial-flow compressor to be used for a gas turbine or the like have been normally located at a single stage. However, an axial-flow compressor of high pressure ratio has variable stator vanes located at a plurality of stages in general (refer to JP-2006-322456-A and the like).